/**
 * @author ：wang-ting
 * @Date：2025/3/21 23:09
 */
import java.util.Scanner;
public class CylinderVolume{
    public static void main(String[] args){
        Scanner input = new Scanner(System.in);
        double radius = input.nextDouble();
        double height = input.nextDouble();
        double volume = Math.PI * radius * radius * height;
        System.out.println(volume);
    }
}